Heat exchanger



Nov. 24, 1936; J. PRICE HEAT EXCHANGER Filed Dec. 10, 1931 2Sheets-Sheet 1 INVENTOR ATTORNEYS Nov. 24, 1936. J, PRICE 2,061,980

' HEAT EXCHANGER Filed Dec. 10, 1931 I 2 Sheets$heet 2 INVENTOR PatentedNov. 24, 1936 UNITED STATES PATENT OFFICE HEAT EXCHANGER DelawareApplication December 10, 1931, Serial No. 580,071

2 Claims. (Cl. 257-239) This invention relates to heat exchangers of thetype in which a plurality of tubes are placed in a containing shell andwhich are commonly known as shell-and-tube or surface type heat 5exchangers.

This type of heat exchanger is used principally in transferring heatbetween two liquids, such as in oil refining operations and'the like,and in transferring heat between a liquid and a gas as,

for example, in steam power plants and indus- I trial establishments.When used for transferring heat between two liquids, one liquid ispassed through the shell of the exchanger and comes in contact with theoutside surfaces of the tubes andthe other liquid is passed through thetubes, and the transfer of heat between the liquids takes place throughthe walls of the tubes.

the gas or vapor is usually passed into the shell and the liquid forcedthrough the tubes.

Inthe particular form of shell-and-tube orsurface type of heat exchangerwith which this invention is concerned, the tube bundle is secured ateach end in a tube sheet and means are provided within the shellcontainingthe tube bundle .for conducting the fluid so that it makes twoor more passes through the tube bundle before being discharged.

Inasmuch as the tubes are usually made of a 3 different metal then theshell and normally operate at a temperature different from that of theshell, the relative thermal expansion between the tubes and the shellmust be compensated for. To this end, one end of the tube bundle isanchored at its tube sheet to the shell, while the other end of the tubebundle and its tube sheet is supported so as to allow it to move bodilywithin the shell in response to thermal expansion or contraction Also,the floating head is of a diameter sufficiently small to permit readyremoval of the entire tube 50 bundle as a unit, including the tubes andboth tube sheets, for purposes of repair and periodic cleaning,especially when oil and other viscous liquids are used therein. In orderto effectively seal the connection be- 65 tween the floating tubesheetand the cap of the In trans ferring heat between a liquid and gasor vapor,

floating head, a very tight joint between them must be provided. It hasbeen common practice heretofore to employ clamping devices which holdthe cap and the floating tube sheet securely together and yet may bereleased readily to enable 5 the heat exchanger to be readilydisassembled for cleaning and removing and replacing tubes and the like.These clamping devices usually include various kinds of so-calledsectional rings to enable ready disassembling of the floating head andlo these have been found to be generally satisfactory, except that thesectional clamping rings have a tendency to cock, rotate, or cant aboutthe inner periphery of the tube sheet, which they are intended to clampsquarely and securely to the 15 cap, when the clamping means, such asbolts, are tightened down.

It is the principal object of this invention to provide a heat exchangerin which the floating tube sheet is clamped securely and squarely to 20the cap of the floating head without the use of sectional rings or otherclamping means which are subject to misalignment caused by cooking orcanting with respect to the floating tube sheet.

In accordance with this object, the heat exchanger includes a tubebundle having tube sheets at each end, one tube sheet being anchored tothe shell in the usual way, and the other tube sheet being arranged tofloat in the shell to accommodate relative thermal expansion between thetubes and shell. The cap, into which one portion of the tubes dischargesand which redirects the fluid into another portion of the tubes, engageswith its rim the outer face of the floating tube sheet and the floatingtube sheet is held against the cap rim in clamping relation by aplurality of separate spaced clamping elements anchored to the cap andhaving a head or other lateral extension or hook overlying the edge ofthe floating tube sheet for clamping it to the cap llm.

In this construction, the clamping members, when drawn tightly at spacedintervals over the edge of the floating tube sheet, secure the lattersquarely and securely to the cap rim over a gasket, so that there is notendency toward looseness or leakage. The clamping members may takevarious forms such as'hook-headed bolts, studs with separate heads ofdifferent shapes, and the like. The tube bundle including the floatingtube sheet is of such dimension as to be readily removable as a unitfrom the shell for repairing and cleaning purposes.

For a better understanding of the invention,

\ reference is made to the accompanying drawings, in which Fig. 1 is alongitudinal section of a heat exchanger embodying the construction ofthe present invention;

Fig. 2 is an expanded view of the floating head consisting of thefloating tube sheet, the cap, and the clamping members;

Figs. 3 and 4 are, respectively, a partial section and a partial faceview of the edge of the floating head, showing the clamping membersemployed in the arrangement of Figs. 1 and 2, and

Figs. 5 to 14, inclusive, are views of modified forms of clampingmembers applied tothe floating head.

In these drawings, the heat exchanger includes the longitudinalcylindrical shell I having the inlet I I at one side and the outlet I2at the opposite side, whereby a fluid such as steam, water, oil or thelike, may be circulated through the shell. Supported within the shellII! is a tube btmdle I3 made up preferably of a relatively large numberof small, thin-walled tubes. These tubes are expanded at the right-handend into a fixed tube sheet I4 and at the left-hand end into a movableor floating tube sheet I5. In order to cause the liquid entering at theinlet II to pass longitudinally of the shell I0 and the tube bundle I3,a baille plate I6 extends from the fixed tube sheet I4 centrally'of theshell I0 and terminates at a point near the opposite end thereof.

The other fluid, such as oil for example, enters at the right hand endof the exchanger through the inlet I1, which delivers it to a chamber I8from which it flows into the tubes of the tube bundle I3 lying on theupper side of the dividing partition I9. The liquid passing throughthese tubes is discharged into the floating chamber 20 at the left handend of the exchanger, this chamber being formed between the cap 2| andthe floating tube sheet I5, to which the cap 2| is secured in a mannerto be described. This chamber redirects the fluid into the tubes of thelower portion of the tube bundle I3, whereby the liquid is returned tothe right hand end of the exchanger and discharged into a chamber 22 onthe lower side of the partition I9, from which it passes out of theoutlet 23.

The shell I0 is provided at its right hand end with a connecting flange24 and at its left hand end with a similar connecting flange 25. Thefixed tube sheet I4 is clamped rigidly between the flange 24 and thecastings 26 containing the inlet I1 and the outlet 23, by means of aplurality of long bolts 21. The shell In is closed at its lefthand endby means of a large dome-like cover 28, which is secured to connectingflange 25 by means of bolts 29. The liquid passing through the shell I0is free to circulate within the dome-like cover 28 around the floatinghead of the tube bundle lustrated in Fig. 5, the bolt 4| formed by thecap 2| and the floating tube sheet |5.

This floating head is supported centrally in the dome-like cover 28 andthe tube bundle I3 is supported centrally in the shell ID by means of anannular disc30 mounted on the tube bundle I3 near the left hand end ofthe exchanger. This disc has a large central opening for the freepassage of the fluid in the'shell and is slidable axially in the shellIII in response to the relative thermal expansion between the tubebundle I3 and the shell I0 and remaining stationary parts of theexchanger. tween the tube bundle I3 and the shell l0 and remainingstationary parts of the exchanger takes This relative thermal expansionbesiderably. The floating tube sheet I is of slightly smaller diameterthan the inside diameter of shell I, so that it can be withdrawn fromthe shell I0 when the tube bundle I3 is removed.

Cap 2| is provided with a thickened rim 3| having a plurality of holes32 arranged in equally spaced relation around its periphery. The innerface of cap rim 3| is provided with the counterbore 33, shown especiallyin Figs. 2 and 3 and with the narrow lip or ridge 34 at its outerperiphery. The floating tube sheet I5 is adapted to seat in thecounterbore 33 of cap 2| over a sealing gasket 35, and the inner edge ofthe floating tube sheet I5 is provided with the recess-36.

As shown in Figs. 1 to 4, inclusive, studs 31, threaded at each end, areinserted through the peripheral holes 32 so that their inner endsproject inwardly around the periphery of the floating tube sheet I5,when the latter is seated in the counterbore 33 of the cap 2|. The innerends of these studs 31 are threaded into blocks 38, which have a lateralextension 39 overlying the edge of the floating tube sheet I5, as shownespecially in Figs. 1 and 3, these extensions 39 of the block 38 beingseated in the recess 35 of the floating tube sheet I5.

When the nuts 40 are tightened down on the studs 31 over the outer faceof the cap rim 3|, the blocks 38 are drawn tightly against the innerface of the tube sheet I5 and against the peripheral lip or ridge 34 ofthe cap rim 3|. It will be seen that the ridge or lip 34 of the cap rim3| holds the spaced blocks 38 against rocking or canting in acounter-clockwise direction about the periphery of the floating tubesheet l5, and that the extension 39 which overlaps the floating tubesheet I5 lies locked in the recess 36 thereof in such a way that anymovement of the block 38 about the lip or ridge 34 as a fulcrum wouldonly tend to clamp the tube sheet I5 more securely in the counterbore 33of cap 2| and compress gasket 35 further.

Accordingly, by means of these spaced clamping members 38-39, whichoverlap the floating tube sheet I5 at spaced intervals around itsperiphery, the floating tube sheet I5 is clamped squarely and securelyto the cap 2|. Also, simply by relieving these clamping members byloosening nuts 40, they may 'be rotated so as to with draw extension 39from out of contact with floating tube sheet I5, whereby the floatinghead may be disassembled without actually removing the clamping members3839. I

In the modification of the clamping means ilpasses through both the caprim 3| and the clamping block' 42. The abutting surfaces of the cap rim3| and the block 42 are made perfectly flat, but the inner face of thefloating tube sheet I5 is provided with a radially inwardly sloping ortapered annular recess, into which the correspondingly shaped extension43 on the block 42 fits closely. The gasket 44 is clamped between theouter face of the floating tube sheet l5 and the counterbore 45 in thecap rim 3| in which the floating tube sheet l5 lies. It will be seenthat as the bolt 4| is tightened down, the tapered extension 43 is soshaped as to seat more tightly into the corresponding annular recess offloating tube lheet that just described in connection with Fig. 5, ex-

cept that the abutting faces 46 of the block 42 and the cap rim 3| areconical and dished together, so that when the-bolt 41 is tightened down,the block 42 is not only locked more selaterally extending head as ofthe T-bolt 49 jointly engages the lip 50 of the cap rim 3| and the innerface of the floating tube sheet I5. The gasket 5| lies between the caprim 3| and the floating tube sheet l5. It will be seen that, as

the T-bolt 49 is tightened down, any tendency of the head 48 to rocktakes'place about lip 50 of cap rim 3| as a fulcrum, so that theoppositeor inner end of the head 48 of the T-bolt 49 serves to force thefloating tube sheet into more intimate contact with the gasket 5| andthe cap rim 3|, whereby no rotating or canting of the T-bolts 49 cantake. place in a counter-clockwise direction.

Fig. 8 is a face view illustrating the arrangement of the T-bolt in thisconstruction.

Figs. 9 and 10 illustrate a bolt 52 having ahook head 53, which overlapsthe inner face of the floating tube sheet I5, the lip 54 of the cap rim3| preventing the, hook-headed bolt 52 from moving outwardly or cantingaway from the outer periphery of the floating tube sheet |5. With thisarrangement, it is only necessary to remove or loosen the T-bolt 52 torelease the cap 2| from the floating tube sheet 15, and the floatingtube sheet and the cap 2| may be as readily assembled simply byinserting and tightening down the bolts 52. The gasket 55 between thefloating tube sheet l5 and the cap rim 3| serves to seal the connectionbetween them.

The modifications illustrated in Figs. 11 and 12 and in Figs. 13 and 14are similar, in that the block 56 overlaps'both the lip 51 of the caprim 3| and the outer face of the floating tube sheet l5, to hold thelatter in place against the cap2| over the gasket 58; Instead of beingpassed entirely through the block 56, as is the bolt 59 in thearrangement of Figs. 11 and 12, the stud 60 is threaded through theblock 56 and is tightannular recess thereof.

ened down on its opposite end by means of the nut 6|, in the arrangementillustrated by Figs. 13 A and 14. In each of these modifications, it isonly necessary to release bolt 59 or the stud 60 to release the floatingtube sheet Hi from the cap 2| and the cap 2| and floating tube sheet l5may be as readily assembled by replacing and tightening down the blocks56 by means of the corresponding bolts 59 or studs 60.

It will be seen that in each of the modifications of the floating headclamping means illustrated and described herein in connection with theinvention, the usual sectional or split ring is eliminated and separatespaced clamping members are employed instead, and that these clampingmembers may take various forms, so long as they individually clamp thefloating tube sheet to the cap rim and are so locked to the cap rim andfloating tube sheet as to prevent'canting or cocking around the outerperiphery of the tube sheet. In fact, in the various modifications ofthe inventionillustrated and described herein, the more these clampingmembers are tightened the less is their tendency to cant or rotate awayfrom or about the periphery of the floating tube sheet. Also, in eachcase the clamping members may be readily removed separately or with thecap so that the, entire tube bundle including the floating tube sheetmaybe withdrawn through the shell of the heat exchanger, the tube sheetbeing made of such diameter as to permit its withdrawal through the heatexchanger shell.

, Although the invention has been described in conection with a two-passheat exchanger, it is to be understood that the invention is applicablewith equal facility to a single pass heat exchanger or otherapparatusrequiring a tightly sealed connection of this type.

I claim:

1. In a heat exchanger, the combination of a shell, a tube bundletherein, a tube sheet for one end of the tube bundle, a cap for saidtube sheet having a rim engaging the outer face of the tube sheet, saidcap rim having a conical seat in its inner face, and a clamping memberhaving a tapered surface cooperating with the conical seat of the caprim secured to the latter and overlapping the inner face of the tubesheet.

2. In a heat exchanger, the combination of a shell, .a tube bundletherein, a tube sheet for one end of the tube bundle, a cap for saidtube sheet having arim engaging the outer face of the tube sheet, saidcap rim having a conical seat in its inner face and said tube sheethaving a tapered annular recess in its inner face, and a clamping memberhaving a tapered surface cooperating with the conical cap rim seat and atapered extension overlapping the inner face of the tube sheet andcooperating with the tapered JOSEPH PRICE.

